Solenoid swung limit switch assembly



Nov. 23, 1965 A R. CHASAR 3,219,770

SOLENOID SWUNG LIMIT SWITCH ASSEMBLY Filed Feb. 23. 1961 :Iijff INVENTOR.

firm/wars United States Patent Ohio Filed Feb. 23, 1961, Ser. No. 91,250 6 Claims. (Cl. 200-47) This application is a continuation-in-part application of my copending United States Patent application Serial No. 66,776, filed November 2, 1960, now Patent No. 3,139,994 and entitled, Mechanical Load Handling, Trans fer and Storage Equipment.

This invention relates to improvements in a switch assembly and more particularly to a solenoid operated limit switch assembly.

An object of the present invention is to provide a limit switch assembly having an actuator arm movable between inoperatable and operatable positions with the switch adapted to be actuated in the operatable position.

A further object of the present invention is to provide a limit switch assembly wherein the movement between these positions is a swinging movement of the limit switch unit and actuator arm about a pivot.

A further object of the present invention is to provide a limit switch assembly characterized by its inexpensive manufacturing cost, structural simplicity, ease of assembly of its component parts, strong and sturdy nature, low operating cost, operating efiiciency, adaptability to use any conventional limit switch, long and accurate switch wear life, etc.

Other features of this invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from the accompanying drawings and description and the essential features will be set forth in the appended claims.

In the drawings,

FIG. 1 is a side elevational view of the limit switch assembly disclosed herein mounted on a supporting frame with the actuator arm thereof shown in solid lines in inoperatable (retracted) and unactuated position and shown horizontally extending in dot-dash lines in operatable (advanced) and unactuated position before movement in the actuating direction and being shown diagonally downwardly toward the left in dotted lines after movement in the actuating direction to the switch actuated positions;

FIG. 2 is a top plan view taken generally along the line 2-2 in FIG. 1;

FIG. 3 is a vertical sectional view taken generally along the line 33 in FIG. 1 through a pivot; while FIG. 4 is a schematic illustration of the interior construction of a conventional limit switch adapted to be used in this assembly.

Before the construction here illustrated is specifically described, it is to be understood that the invention here involved is not limited to the structural details or arrangement of parts here shown since a construction embodying the present invention may take various forms. It also is to be understood that the phraseology or terminology herein employed is for purposes of description and not of limitation since the scope of the present invention is denoted by the appended claims.

Those familiar with this art will recognize that this invention may be applied in many ways. One suitable application is to use this limit switch assembly shown as having limit switch LS8R in FIGS. 9A and 23 in my aforementioned copending United States patent application. The operation described herein will be generally the same as in my aforesaid copending application.

Limit switch assembly 10 in FIGS. 1 3 includes switch unit 12, actuator arm 20 and a connection or connecting means 22 operatively connecting unit 12 and arm 20. Switch unit 12 has a mounting face 12a and encases any suitable limit switch construction. Such switch unit 12 is shown schematically in FIG. 4 as including by way of example actuatable stationary contacts 13, 13, 14 and 14; and movable contacts 15a and 15b located respectively at upper and lower ends of movable contact plate 15 rigidly carried by arm 19. Arms 19 and 20 are rigidly secured to pivot shaft 24 of connection 22 so that movement of actuator arm 20 by force F from the solid line position to the dotted line position will cause shaft 24, rotatably mounted in the housing of switch unit 12, to move counterclockwise about axis A against the force of spring 18 to move contact plate 15 to the dotted line position to close stationary contacts 14, 14 by movable contacts 15a and 156 while opening normally closed contacts 13, 13. Upon release of actuating force F on arm 20, spring 18 will return the parts to the solid line position; open contacts 14, 14; and close contacts 13, 13. Actuator arm 20 includes link 26 having rotatably secured to its distal end a switch actuating, trip engaging roller 28 by pivot pin 29. This limit switch is thus moved from the untripped or unactuated position P1 to the tripped or actuated position P2 by pivotal movement of arm 20 in actuating direction D1.

This structure thus far described applies generally to any conventional limit switch, and it should be readily apparent that any satisfactory or conventional limit switch construction may be used within switch unit 12 to be actuated by oscillation of pivot shaft 24 herein because the schematic construction in FIG. 4 is shown only for purposes of illustration. One suitable form of construction of said switch unit 12 is shown in United States Patent No. 2,352,815, issued July 4, 1944, to H. L. Van Valkenburg, and entitled, Electric Switch.

Limit switch assembly 10 herein is disclosed as'being mounted and operable in generally the same manner as the limit assembly, including limit switch LS-8R, in FIG. 9A of the copending application. As in this copending application, frame 32 is adapted to be driven in vertical direction D2 by a suitable motor (not shown) by a circuit through closed contacts 13 in switch unit 12 connected to this supporting frame 32. A stationary frame has located at spaced apart locations along direction D2 a pair of horizontally aligned stationary frame arms 35 at each location with each arm pair having a trip surface 3ST. Frame 32 carries a load vertically in direction D2; is adapted to be stopped at a preselected trip surface 3ST; and after actuator arm 20 moves to the actuated position P2, suitable mechanism on frame 32 transfers the load onto the shelf provided by the pair of frame arms 35 corresponding to this trip surface 3ST. As frame 32 moves in direction D2, roller 28 engages trip surface 3ST to move the switch components from unactuated position P1 in actuating direction D1 to actuated position P2 in FIGS. 1 and 4 because connection 22 includes a pivot element, comprising pivot shaft 24, pivotally connecting actuator arm 20 to switch unit 12 for arcuate actuating movement of arm 20 in direction D1 about pivot axis A when roller 28 of arm 20 engages with trip 3ST during movement of frame 32 in direction D2 relative to trip 3ST. Movement in actuating direction D1 causes switch contacts 13 to open and contacts 14 to be closed by contact plate 15 in the dotted line position in FIG. 4 upon switch actuation.

Switch unit 12 is connected to supporting frame 32 by securing means permitting relative movement therebetween.

Switch unit 12 is secured by two nut and bolt units 38, extending through through holes in the housing of switch unit 12 and located at diagonally opposite corners, for securing it onto mounting plate 39. Mounting plate 39 is pivotally connected to frame 32 by shouldered stud 40 screwed into threaded hole 32a in frame 32 to provide a pivot extending parallel to pivot shaft 24 but laterally spaced therefrom.

Connection 22 may take any suitable form and includes herein pivot element 45 pivotally connecting actuator arm 20 to switch unit 12. Element 45 includes pivot shaft 24 extending from switch unit 12, bracket 47 secured to shaft 24 against rotation by clamp screw and nut unit 48, and parallel grooves 49 to secure link 26 of arm 20 against endwise movement when lock plate 52 is secured by lock screw 50 screwed into a threaded hole in bracket 47.

In the aforesaid copending application, there are a plurality of vertically spaced apart pairs of frame arms 35, and frame 32 is adapted to stop in horizontal alignment with any selected one of these pairs of arms 35 upon movement of actuator arm 20 from unactuated position P1 to actuated position P2. However, during travel in vertical direction D2, it is desirable to keep actuator arm 20 in inoperatable or retracted position P4 during travel past unselected arms 35 and then advance arm 20 to operatable or advanced position P3 immediately before arriving at the preselected arms 35 with which frame 32 is to be stopped in horizontal alignment. This advancing action is provided by power means mentioned hereinafter having a solenoid 62 electrically energized. This electrical energization may be caused in any suitable manner, such as by manually closing an energizing circuit at the appropriate time or by-a counter mechanism counting vertically spaced arms 35 or the distance traveled by frame 32 in direction D2, as disclosed in said copending application.

This power means is provided for moving arm 20 relative to frame 32 in direction D4 (non-parallel to actuating direction D1) between inoperatable or retracted position P4 with arm 20 located to be out of actuating alignment with trip 3ST during travel of frame 32 in direction D2 and operatable or advanced position P3 with arm 20 located to be in actuating vertical alignment with trip 3ST. This power means takes the form of an electrically energizable solenoid 62 for moving arm 20 in direction D4 from position P4 to position P3 upon energization of the solenoid by its lead wires 62a and tension type helical spring 64, or other suitable resilient means, for moving arm 20 in opposite direction D5 from position P3 to position P4 upon de-energization of solenoid 62. Solenoid 62 includes a conventional coil member 62b having telescoped therein relatively movable armature member 620 movable outwardly to push switch unit 12 in direction D4 upon energization of coil 62b.

Solenoid 62 and spring 64 each operatively connect switch unit 12 and frame 32 so that energizing solenoid 62 pushes armature 62a outwardly against pin 65 to swing switch unit 12 and arm about pivot 40 in counterclockwise direction D4 between these positions and de-energizing solenoid 62 permits spring 64 to move switch unit 12 in opposite clockwise direction D5. Solenoid coil 62]) is secured to frame 32 with its armature 62c adapted to abut against pin 65 secured to mounting plate 39. Spring 64 is secured at opposite ends to pins 66 and 67 respectively secured to frame 32 and mounting plate 39.

The advantages of this construction are many, and especially when used in the circuit disclosed in the aforesaid copending application. First, a conventional limit switch, having an arm 20 secured against endwise movement to bracket 47 by lock plate 52 secured to bracket 47 by screw 50, can be easily converted to this design by merely adding mounting plate 39, pivot stud 40, solenoid 62, spring 64 and pins 65, 66 and 67. Second, longer and more accurate wear life is obtained by switch unit 12 because arm 20 is normally in position P4 so does not have to be overworked by engagement and actuation by every trip surface 3ST but is only extended to operatable position P3 at the preselected trip 3ST to be actuated only once where desired. Third, no holding contacts are required in the operating circuit in parallel with contacts 13, 13 to maintain energized the driving motor of frame 32 as switch unit 12 is actuated by each trip 3ST before the selected stopping position is reached. Fourth, one can select, either manually or by suitable counting mechanism, the time to advance arm 20 from position P4 to position P3 for actuation in direction D1 from position P1 to position D2 at the desired trip surface 3ST so that undesired trips 3ST may be passed during movement of frame 32 in direction D2 without switch actuation. Fifth, this limit switch assembly 10 may be used for many different purposes in addition to that disclosed in the aforesaid copending application, such as on hoisting devices, conveyors, counting devices, sorting devices, etc. Sixth, frame 32 can be caused to continue movement in direction D2 after being stopped in position P2 in a very simple manner by this construction. De-energizing solenoid 62 will cause spring 64 to move arm 20 from position P2 to position P4 to close contacts 13 and permit travel of frame 32in direction D2 in the same manner as earlier described.

Various changes in details and arrangement of parts may be made by one skilled in the art without departing from either the spirit of this invention or the scope of the appended claims.

What is claimed is:

1. A switch adapted to be mounted to a supporting frame and having an operative member; said operative member comprising an arm pivoted to said switch, a nonpivoted end of which is engageable with a relatively moving trip thereby actuating said switch; a solenoid; means mounting said solenoid for movement with the frame in use; means operatively connecting said solenoid with said arm and effecting movement of said arm relative to the frame from a first position out of actuating alignment with the trip to a second position in actuating alignment with the trip, upon energization of said solenoid; and resilient means moving said arm from said second position to said first position upon de-energization of said solenoid.

2. A switch for mounting upon a supporting frame for actuation by a relatively movable trip; means for pivotally mounting said switch to the frame whereby it pivots in a plane parallel with the direction of relative movement of the frame and trip; an actuator arm pivotally mounted to said switch for arcuate, switch actuating movement in a plane parallel with said first mentioned plane; a solenoid mounted to the frame in use thereof and having an operating member movable upon energization of said solenoid; said operating member abutting said switch in use and pivoting said switch from a position whereby said arm is out of alignment with the trip to a position whereby said arm is in alignment with the trip, when said solenoid is energized;

3. A switch for mounting upon a frame which is movable with respect to a fixed trip; means pivotally mounting said switch to the frame in use to pivot in a plane substantially parallel with the direction of movement of the frame; an actuator arm pivotally mounted to said switch for arcuate, switch actuating movement in a plane parallel with said first mentioned plane and coplanar with the trip; a solenoid mounted to theframe in use adjacent to said switch; said solenoid having anarmature; a spring pivotally biasing said switch against one end of said armature and normally maintaining said actuator arm out of alignment with the trip; said solenoid energizable to move said armature endwise whereby said switch is optionally pivotable to move said actuator arm into alignment with said trip to cause actuation of said switch.

4. A switch for mounting upon a frame which is movable with respect to a plurality of fixed trips; means pivotally mounting said switch to the frame in use to pivot in a plane substantially parallel with the direction of movement of said frame; an actuator arm pivotally mounted to said switch for arcuate switch actuating movement in a plane parallel with said first mentioned plane and coplanar with said trips; a solenoid mounted to the frame in use adjacent to said switch; said solenoid having an armature; a spring pivotally biasing said switch against one end of said armature and normally maintaining said actuator arm out of alignment with the trips; said solenoid energizable to move said armature endwise whereby said switch is optionally pivotable to move said actuator arm into alignment with a selected one of said trips to cause actuation of said switch.

5. A leveling switch for mounting upon a frame which is vertically movable with respect to a plurality of fixed, vertically aligned trips; means pivotally mounted said switch to the frame in use to pivot in a substantially vertical plane; an actuator arm pivotally mounted to said switch for arcuate, switch actuating movement in a vertical plane coplanar with said trips; a solenoid mounted to the frame in use adjacent to said switch; said solenoid having an armature; a spring pivotally biasing said switch against one end of said armature and normally maintaining said actuator arm out of vertical alignment with the trips; said solenoid energizable to move said armature endwise whereby said switch is optionally pivotable to move said actuator arm into vertical alignment with a selected one of said trips to cause actuation of said switch for leveling the frame.

6. Switch leveling means comprising a vertically movable frame; a plurality of vertically aligned, spaced trips disposed adjacent to the path of movement of said frame; a switch pivotally mounted to said frame adjacent to said trips and pivotable in a vertical plane; an actuator arm pivotally mounted to said switch for arcuate, switch actuating movement in a vertical plane coplanar with said trips; a solenoid mounted to said frame in use adjacent to said switch; said solenoid having an armature; a spring pivotally biasing said switch against one end of said armature nad normally maintaining said actuator arm out of vertical alignment with said trips; said solenoid energizable to move said armature endwise whereby said switch is optionally pivotable to move said armature into vertical alignment with a selected one of said trips to cause actuation of said switch for leveling said frame with respect to said selected trip.

References Cited by the Examiner KATHLEEN H. CLAFFY, Primary Examiner.

RICHARD M. WOOD, ROBERT K. SCHAEFER,

BERNARD A. GILHEANY, Examiners. 

1. A SWITCH ADAPTED TO BE MOUNTED TO A SUPPORTING FRAME AND HAVING AN OPERATIVE MEMBER; SAID OPERATIVE MEMBER COMPRISING AN ARM PIVOTED TO SAID SWITCH, A NONPIVOTED END OF WHICH IS ENGAGEABLE WITH A RELATIVELY MOVING TRIP THEREBY ACTUATING SAID SWITCH; A SOLENOID; MEANS MOUNTING SAID SOLENOID FOR MOVEMENT WITH THE FRAME IN USE; MEANS OPERATIVELY CONNECTING SAID SOLENOID WITH SAID ARM AND EFFECTING MOVEMENT OF SAID ARM RELATIVE TO THE FRAME FROM A FIRST POSITION OUT OF ACTUATING ALIGNMENT WITH THE TRIP TO A SECOND POSITION IN ACTUATING ALIGNMENT WITH THE TRIP, UPON ENERGIZATION OF SAID SOLENOID; AND RESILIENT MEANS MOVING SAID ARM FROM SAID SECOND POSITION TO SAID FIRST POSITION UPON DE-ENERGIZATION OF SAID SOLENOID. 